Planting systems used in planting operations typically include a rotatable disc mounted for rotation within a hollow interior of a generally cylindrical two-piece housing mounted at the bottom of a seed hopper. Seeds from the seed hopper flow into a seed chamber within the housing on one side of the seed disc. The seed disc typically includes a plurality of openings formed therein which are located adjacent the periphery of the disc in a circumferential arrangement. As the seed disc rotates, the openings pass through the seed chamber and the seeds are drawn to the openings and are held within the openings where they are retained for later release. In a vacuum seed planting system, for example, the seeds are held in relation to the seed disc by a vacuum source coupled to a separate chamber located on the opposite side of the seed disc from the seeds in the seed chamber.
In a typical arrangement, a series of spaced apart openings located adjacent the periphery of the disc in a circumferential arrangement is provided. This allows for the release of individual seeds at a controlled rate. In some applications, it is desirable to plant several seeds in a tight group such as in the case of cotton planting on hills. To accomplish this, the seed disc must be configured to allow the simultaneous drop of several seeds.
Attempts have been made to provide a seed disc capable of releasing several seeds simultaneously including, for example, providing a disc having a plurality of openings arranged in a radial row, with each opening slightly offset from one another. The disadvantage of this arrangement is that the seeds in a given row are not released simultaneously. As a result, the seeds are not consistently dropped in a tight group.
Accordingly, it would be desirable to have a seed disc that overcomes the disadvantages described above and to provide a simple, and cost effective multiple drop seed disc apparatus.